If you're feeding a diet such as Bml, Tpg, one of the Hpw's they have all the protein gliders need already in them, there is no reason to give them extra except for maybe on cheat nights where they aren't getting the staple part.
Giving them extra proteins while feeding a diet with protein already in it is drastically increasing the protein intake, and changes the amount of vitamins and minerals so they will likely be getting far more OR far less than they need. It will also increase their iron intake which can be very hard on their internal organs. I know it seems like it's not a big deal, but it is.
The diets have feeding instructions for a reason, the fruits and veg, portion size of the staple and of the fruits and veg are all specific to that diet and should be followed as it's written for that diet.
Using one diet ( lets say bml ) but following fruit and veg listed for another diet ( lets critter love hpw fruits n veg salads ) DOESN'T WORK. The fruit and veg listed for bml help keep the over all diet balanced. Meaning they get the appropriate amount of vitamins and minerals ( including protein and calcium ) from every part of the diet INCLUDING the fruit n veg.
If the recipe says feed 1 Tablespoon fruit and 1 Tablespoon veg PER glider, then that's what you should be feeding them.
Demow, your feeding a pellet diet with fruits n veg n a protein...... I'm not sure who your wise sources are, but I'd keep researching and fact checking. People post their opinions a lot but that doesn't mean they are wise or even knowledgeable about the topic they have opinions on.
Maeganw, some gliders really don't "gain" weight or seem to grow until their body is ready to, no matter what diet you feed. If your glider is a joey he/she may not fill out or have a big growth spurt till they are closer to a year old. Keep track of his or her weight every now n then though, get a kitchen scale that weighs in grams so you can keep track of the growth. I had a female that stayed at like 65 grams for months, then all the sudden she was at 90 grams when she hit a year old.
Diets are controversial, and confusing especially for new owners. If you have specific questions about the diet I'd be happy to give you contact information to the diet creator, questions are best answered by the creator of the diet they know it better than anyone else.